Steroid compounds having a 16, 17-ring substitution have been described. Chemical Abstracts 89: 215660p (Kamernitskii A V. et al.) describes a steroid compound comprising a 16,17 anellated 5- or 6-membered ring and an acetyl group at position 17. The compounds disclosed in this publication however differ from the steroid compounds according to the present invention in that the carbon atom at position 11 carries a hydrogen atom.
Chemical Abstracts 123: 285604t (Wang, J. et al.) discloses steroid compounds having a 10-membered E-ring with two triple bonds, a hydroxyl group at position 17, and a hydrogen atom at position 11.
EP 411.733 (Schering AG) discloses a steroid compound having a 6-membered E-ring, the carbon atom at position 17 being involved in a CO-bond. The compounds disclosed in EP 411733 however differ from the steroid compounds according to the present invention in that the carbon atom at position 11 carries a (substituted) aryl group. These compounds are disclosed to be competitive antagonists for progesterone.